1. Field of the Invention
The present invention concerns a metatarsal guard which is located in the upper of a safety shoe or work boot, for protecting the metatarsal region of the wearer's foot from injury caused by the impact of a falling object.
2. Description of the Prior Art
Safety shoes and work boots are commonly required to protect industrial workers from injury to the foot caused by falling objects. Most safety shoes incorporate a box toe, formed of steel, hardened plastic or other suitable material, to protect the wearer's toes from falling objects. Metatarsal, or instep, guards are also provided to protect the wearer's metatarsal arch, or instep.
U.S. Pat. No. 5,457,898 issued to Fortin et al discloses a plastic metatarsal guard inserted in a safety shoe upper. The guard comprises an arch extending over the wearer's instep from the sole of the shoe on one side of the wearer's foot to the sole on the other side of the wearer's foot. The rear portion of the metatarsal guard protects the metatarsal region of the wearer's foot from the impact of falling objects by absorbing the impact. The metatarsal guard disclosed in the patent is relatively involved compared to the simple, but effective, metatarsal guard of the present invention. Thus, for example, the metatarsal guard disclosed in U.S. Pat. No. 5,457,898 includes longitudinal tongues formed by longitudinal slits which spread apart to follow the movement of the foot and to enhance the flexibility of the metatarsal guard during walking. Furthermore, to compensate for the loss in impact absorption caused by the longitudinal slits, the metatarsal guard requires an integral flap which folds over the top surface of the longitudinal slits.
The metatarsal guard of U.S. Pat. No. 5,457,898, like the metatarsal guard of the present invention, allows the load from a falling object to be transmitted from the metatarsal guard to the sole of the footwear. The arch extending over the wearer's instep in U.S. Pat. No. 5,457,898 is much wider than the arch of the present invention and indeed, the arch disclosed in the patent is so wide that two relatively long side slits are required to facilitate flexing of the metatarsal guard during walking, and to facilitate flexing of the wearer's foot in the crouching position. The metatarsal guard disclosed in U.S. Pat. No. 5,457,898, like the metatarsal guard of the present invention, includes a forward position which extends over the top surface of a toe cap so that the loads from a falling object are also transmitted to the toe cap. U.S. Pat. No. 4,237,170 issued to Griswold also discloses a rather complex metatarsal guard comprising a plurality of elongated generally arched-shaped transversely extending rigid strips which are articulated together to provide a protector assembly.